fix: optimize height calculations for ask_user dialog (#19017)

packages/cli/src/ui/components/messages/ToolConfirmationMessage.tsx

@@ -235,6 +235,10 @@ export const ToolConfirmationMessage: React.FC<
       return undefined;
     }
 
+    if (handlesOwnUI) {
+      return availableTerminalHeight;
+    }
+
     // Calculate the vertical space (in lines) consumed by UI elements
     // surrounding the main body content.
     const PADDING_OUTER_Y = 2; // Main container has `padding={1}` (top & bottom).
@@ -253,7 +257,7 @@ export const ToolConfirmationMessage: React.FC<
       1; // Reserve one line for 'ShowMoreLines' hint
 
     return Math.max(availableTerminalHeight - surroundingElementsHeight, 1);
-  }, [availableTerminalHeight, getOptions]);
+  }, [availableTerminalHeight, getOptions, handlesOwnUI]);
 
   const { question, bodyContent, options } = useMemo(() => {
     let bodyContent: React.ReactNode | null = null;